A program was established in 1984 to study the regulation of cell motility in developing systems. The basic research projects supported by the program now include 1) cell motility, chemotaxis and the role of the cytoskeleton in Dictyostelium, 2) the role of caldesmon and the tropomyosins in vertebrate cell motility, and 3) the role of regulatory cascades in growth cone motility during neuronal development and modification. A core Facility was originally established which provides computer-assisted image processing and motion analysis systems for use by participants. The Core Facility has evolved into a technology development facility as well as a service facility for the development of advanced 2D and 3D motion analysis systems. The program also sponsors the Cell Motility Seminar Series, in which outside speakers present seminars on topic of interest to the Program, a Junior Symposium, in which graduate students and post-docs present seminars, and the Annual Motility Symposium, a half day formal symposium including senior scientists from the University of Iowa and other universities. The program has stimulated collaborations between program participants which in all cases have led to joint publications, and a number of new projects related to the developmental biology of cell motility. In the next program project, individual projects will include the following: 1) chemotaxis and the involvement of select cytoskeletal elements relying primarily on 3D dynamic image analysis systems recently developed in the Core Facility (Soll lab); 2) the roles of caldesmon, tropomyosin and the myosins in intracellular and cellular motility, and cytokinesis in animal cells (Lin lab); 3) the role of regulatory cascades and the cytoskeleton in neuronal development and plasticity (Wu lab); and 4) development of an advanced 3D dynamic image analysis system and "direct image" reconstruction software (Voss, Core Facility). In addition, the Core Facility will function as a service facility, and the Cell Motility Seminar Series, the Junior Symposium and the Annual Motility Symposium will be continued. This program project focuses on the general them of cell motility in development, and continues to obtain vitality from the constant interactions of the participants.